At least 19 people were killed and seven others were reported missing after rainstorms described as once-in-a-century phenomenon hit different provinces in south China.

The rainstorms slashed Guangzhou, Zhaoqing and Qingyuan cities and caused floods, house collapses and mud flows, the provincial flood control and civil affairs authorities said.

More than 140,000 people were affected, 21,000 were evacuated and 1,143 houses collapsed, state-run Xinhua news agency reported.

Rainstorms in Guangdong have left 15 dead and five missing since Wednesday and affected 800,000 people, with accumulative precipitation of 628 mm in Shanwei City, officials said.

Sixteen national or provincial highways have been closed because of the downpour. Guangdong provincial authorities have activated an emergency response system and sent working teams and relief materials to the affected areas.

Downpours also swept southwestern Guizhou Province, as well as Hunan and Jiangxi provinces in south China. Three people died in Guizhou due to a rainstorm, with precipitation of 145.7 mm in Shiqian County.

In Jiangxi, 5,000 residents in Pingxiang city were trapped by floods and more than 4,000 locals were evacuated.

In Quannan County of Jiangxi, a rescuer died after his yacht capsized in a river due to engine failure while searching for a missing middle school student.